The kiss for humans is undoubtedly a summit of human romanticism or the closeness between two people, and when we focus on the animal world and see them doing our ‘Eskimo kiss’ by bringing their noses together, we believe that they also they are romanizing. But the reality is that touching noses mutually is not just a sign of affection, but a high-speed data transfer.
What has been seen. A new scientific review published in 2026 in Evolution and Human Behavior has brought order to decades of scattered observations of this type of communication. Their conclusion is quite clear: from bats to pigs and rats, nose-to-nose contact is one of nature’s most sophisticated communication tools. And yes, our human kiss could simply be a version 2.0 of this ancient biological mechanism.
The second olfactory system. To understand why animals rub their noses, you first have to understand that most mammals smell the world in stereo, but with two different systems. The first of these is the main olfactory system that detects volatile odors such as the smell of rain.
But the second goes much further, since is centered on the vomeronasal system (VMO)which is a structure specialized in detect pheromones and non-volatile substances.
Its importance. This second olfactory system is the one that interests us in this case, since the signals captured by this organ do not pass through the usual filters of rational thought; They rapidly project to the amygdala and hypothalamus, the command centers for emotion, aggression, and sexual behavior.
This way, when two beavers they bump their noses, they are not “greeting” each other politely; you are injecting pure chemical information about your hormonal status and health directly into your limbic system.
The language of noses. The touch of two noses has many more functions than a simple sign of affection, and depending on the species, a touch of the nose can be a sentence of submission or a medical check-up. In the case of rats, nose-to-nose contact is a political tool.
The queen uses intense nudging and nose contact not to demonstrate love, but to exert dominance and reproductive suppression. It’s their way of chemically reminding subordinates who’s boss and inhibiting their ability to reproduce.
The success of the pigs. In livestock farming and applied ethology, nasal contact between piglets is a performance metric. The studies cited by Rasmussen show a direct correlation: a greater frequency of nasal contacts is associated with greater weight gain and survival. This makes contact function as a social cohesion mechanism that reduces stress and improves the well-being of the group.
The hedgehog accident. Although we may think that all contacts are social, in solitary animals such as the European hedgehog it has been documented that many of these encounters are accidental collisions. Basically, since they have very poor vision, they approach each other olfactorily until they collide.
What is interesting is what happens next in cats and other small mammals: sudden immobility. The animal “hangs” momentarily processing the chemical sensory overload it has just received.
The modern kiss. Although we do something similar with kisses, even with Eskimo kisses, the truth is that we have lost a large part of the functionality of the vomeronasal organ. But it is true that we maintain the behavior.
A study carried out in 2023 published in Science dismantled the myth that the kiss is a recent invention, since it was already seen in Mesopotamia and Egypt that The lip-to-lip kiss existed 4,500 years ago.
Its meaning. Anthropologists suggest that behaviors such as hongi Maori, the honi Hawaiian or the misnamed “Eskimo kiss” (kunik) of the Inuit are the missing links. In these practices, the goal is not the touch of lips, but rather the sharing of breath and smell in intimate proximity.
The human kiss, with all its cultural load, could be an evolutionary remnant of that biological need to get close enough so that our brains could chemically “read” each other. What for a bat is an identity recognition, For us it has become a sign of intimacy, but the underlying hardware has a common origin: the need to communicate what cannot be said with words (or with grunts).
Images | Simon Hurry
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